Adobe Photoshop CS4 - Manual (Page 506)

499 USING PHOTOSHOP CS4
Printing
Last updated 1/10/2010
Edit a spot channel to add or remove color
1 Select the spot channel in the Channels panel.
2 Use a painting or editing tool to paint in the image. Paint with black to add more spot color at 100% opacity; paint
with gray to add spot color with lower opacity.
Note: Unlike the Solidity option in the Spot Channel Options dialog box, the Opacity option in the painting or editing
tool’s options determines the actual density of ink used in the printed output.
Change a spot channel’s color or solidity
1 Double-click the spot channel thumbnail in the Channels panel.
2 Click the color box, and choose a color. Click Color Libraries to choose from a custom color system such as
PANTONE or TOYO.
3 Enter a Solidity value between 0% and 100% to adjust ink opacity for the spot color.
Note: The Solidity and color choice options affect only on-screen previews and composite prints. They have no effect on
printed separations.
More Help topics
“ Create a new spot channel ” on page 497
“ Choose a spot color ” on page 123
Merge spot channels
In RGB or CMYK color mode, you can remove spot channels and merge them into the standard color channels. When
you merge spot channels in CMYK mode, the resulting colors usually don’t precisely match the original spot colors,
because CMYK inks can’t produce the range of colors available from spot color inks.
1 Select the spot channel in the Channels panel.
2 Choose Merge Spot Channel from the panel menu.
The spot color is converted to and merged with the color channels. The spot channel is deleted from the panel.
Merging spot channels flattens layered images. The merged composite reflects the preview spot color information,
including the Solidity settings. For example, a spot channel with a solidity of 50% will produce different merged results
than the same channel with a solidity of 100%.
Adjust overlapping spot colors
To prevent overlapping spot colors from either printing over or knocking out the underlying spot color, remove one
of the spot colors where they overlap.
Use a printed sample of the overprinted inks to adjust your screen display to help you predict how colors will look
when printed.
Note: In some cases, such as when you use varnish and bump plates, you may want colors to overprint.
1 In the Channels panel, select the spot channel with the color you want to print.
2 Choose Select > Load Selection.
To quickly select an image in a channel, hold down Ctrl (Windows) or Command (Mac OS), and click the channel in
the Channels panel.